Eight more people in Indiana have been infected with the variant H3N2 (H3N2v) virus linked to pigs at fairs, state health officials announced today.
Last week Indiana became the first state in the country to report H3N2v infections this summer, and the new cases raise the state's tally to 12, the Indiana State Department of Health (ISDH) said today in a press release.
The earlier cases were reported in people who attended the Grant County fair, and the ISDH signaled that some of the new cases were in those who attended a second event, the Hancock County fair, which was held from the Jun 21 through 28.
The Hancock County fair, located in Greenfield, Ind., was held a week after the Grant County event in Marion. The two towns are about 65 miles apart.
At least 10 people with H3N2v infections were exposed to pigs at the fairs, and one person had contact with swine at his or her home farm.
The ISDH is encouraging people to protect themselves at fairs, and said it and local health departments are continuing to investigate the cases.
So far 29 pigs from the two fairs have tested positive for influenza, the ISDH said, citing Indiana's State Board of Animal Health.
Last year the US Centers for Disease Control and Prevention (CDC) reported 309 infections with H3N2v, and Indiana was one of the hardest hit states with 138 cases. So far this summer no other states have reported H3N2v infections, but health officials have said they wouldn't be surprised to see another wave of cases as the fair season gets underway.
The flu outbreaks linked to fairs are posing difficult challenges for public health officials. Pigs infected with the swine version of the disease often don't look sick, so it's difficult to tell which ones are infected. The Centers for Disease Control and Prevention has said the virus is thought to spread from pigs to people mainly through respiratory droplets, making it difficult to protect people from it.
Jul 3 ISDH press release
Jun 27 CIDRAP News story "Indiana reports four fair-linked H3N2v cases"